Ok so 85K on my 07 with original plugs to my knowledge. I went from stock 275/65/18 BFG's to 295/70/17 Trail Grapples with Auto Springs 2" front/3" block about and mileage went from 15.5 to 14.0 for the first few tanks with the new set up. Now I'm around 12.5 and even got 11.5 one tank. This is hand calculated; multiplying miles driven time 1.035 (the tires are 3.5% more revolutions per mile if my math is right) to get miles, divided by gallons used.

Is something wrong? I figured 13.5-14 for an MT tire. I'm going to do the plugs soon; oil and fuel filter changed regularly. The tank where I got 11.5 was very concerning as this is a daily driven truck 50/50 city/highway.

 

You will see a slight drop in MPG, but it should be from 13-14 not any lower. If you want to see gains I would spend $200 on a standard Edge Evolution, that will give you MPG gains immediately. I went from about 9 MPG to 13 MPG on 37's.

 

Its a simple formula. Lifted truck = less aerodynamic. Larger heavyer tire = more rtational mass. More. agressive and wider tire = more tread slap and heat build up plus more wind resistance. + taller tire = efective gear differance and will throw your odometer off and effect your calculation. your MPG will suffer to some extent depending on how you drive

 

I guess I should have pointed out that this isn't my first lifted truck so I understand the whole great rolling resistance, less aerodynamic stuff. I used to have a 7.3 with 35" Terra Grapplers.

I know the plugs need to get swapped out and probably the coils as well. I think an Evo is in my future.

 

The Evo has saved my bank account.

 

Just found one on Craigslist for $250 with everything including the dash pod. Sound alright?

 

That's cheap I'd get on that.

 

They usually sell on here for 250$ so that's a good price

 

I'll try to snag it. I'll report back my mileage. Thanks for the help fellas!

 

No problem, if you need any Edge help just let us know.